Cold snap tomorrow, early seeding tips (Feb. 20, 2022)

From Linda Gilkeson:

Last year this time we were coming out of a period of very heavy snowfall and sub-zero weather so this February has been quite a pleasant surprise. Now, however, a late cold snap is forecast to materialize starting Monday or Tuesday, depending on where you are, with nighttime temperatures falling well below freezing. If you were lulled into uncovering tender plants (I’m looking at you, citrus growers!), best cover them up again. Plants that have started growing are more vulnerable to cold now than they would have been a month ago. Especially be sure to protect artichoke crowns, which, if they survived the December cold, will have started to grow by now. Also protect half-hardy herbs, such as rosemary, and pull tarps back over beds of spinach, lettuce and other leafy greens for the next couple of nights. We still have a bit of winter to get through, with snowstorms in March not uncommon (and even in early April at higher elevations). Although more frosty nights are undoubtedly coming our way, temperatures don’t usually drop into the extreme cold range after February.

Do continue to keep any root crops in the garden well-insulated with deep mulches to keep the roots cool. We don’t want them to know that spring is here! When they start new growth, they use up sugars in the roots to grow new roots and make flower stalks, with the inevitable loss of flavour and quality. Usually, I dig any remaining carrots, beets, etc. around April 1 and put them in the refrigerator, but this year, given the warm weeks we have had this month, it might be necessary to dig them sooner. As I have been moving aside the thicker mulches over garlic, strawberries and other plants I have been piling it higher on the carrot beds. When you start to see the first tiny leaves emerging from the top of a carrot root, it shows the “spring” message has gotten through and it is time to harvest.

Which brings me to the subject that occupies gardeners this time of year: When to plant? Spring on the coast can be very long, sometimes stretching from late February to June, though often delayed by cold weather in February and even March. It is impossible to give a calendar date when you can plant seeds or seedlings outdoors, but you can use soil temperature as a measurement. Soil thermometers are sold in some garden centres and through Lee Valley Tools and other mail order suppliers. Soil temperature determines germination rate: The warmer the soil, the faster seedlings get going and the less time they spend vulnerable to damping off, cutworms, slugs, birds and other critters. Wait until soil is at least 10oC [50oF] before sowing cool season crops, such as lettuce, cabbage family, spinach. Although some vegetables, such as onions, can germinate in freezing soil, it takes them many months to do so, whereas in warm soil, germination only takes a week or two. Sowing warm season crops, such as beans should wait until the soil is over 15oC [60oC] and we are a long way from that right now.

An indicator that does not work for timing spring planting in our coastal region is the average last frost date. While it can be useful for timing plantings in less geographically complex regions of the continent, such average records aren’t much use on the coast. Here, mountains, fjords, valley and seaside landscapes experience strikingly different frost patterns often from one neighbourhood to the next. As climate change picks up speed and delivers increasingly variable weather, historical averages are also becoming less useful as indicators of future conditions.

The bottom line is that the later you wait to start seedlings, the more likely it is that things will go smoothly (remember, those dang climbing cutworms I am always on about are going to be chomping on leaves of many kinds of plants until the end of April). Of course, the recent warmth might have tempted you to experiment with early sowing, especially if your garden is in a warm, sheltered site. If l you have sown annuals, such as hardy lettuce and spinach, it might work out (…just be prepared to re-seed if it doesn’t).

Beware bolting biennials: Biennial vegetables are less likely to be successful planted early because of the risk of vernalization from a late spring cold spell. Biennials, such as chard, kale, celery, onions and leeks, bolt (flower and go to seed) in their second summer after spending the winter in the garden. The winter chill is the signal that tells them they are in their second summer and it is time to flower. However, if biennial vegetables are sown early enough in the season, they can be fooled by a later period of cool weather in April into responding as if they had experienced winter. The result is that some, or all, of the plants bolt later on in mid-summer. If you have had trouble with biennials bolting prematurely, try waiting to plant until later in the spring. Even though it is quite cold hardy, I don’t sow chard until early May, because it is readily vernalized. The plants produce all year around and through the following spring; I am usually picking the last leaves of the overwintered plants when the first leaves of the new crop are ready to harvest.

Starting seed indoors: Celery and celeriac take a long time to grow from tiny seeds so should be started indoors this month. I will be starting my onions and leek seeds under grow lights in another week or so, having found that end of February timing works better than sowing them earlier. I went into detail on timing of spring sowing last year so I refer you to my February 6, 2021 message for more information: Linda Gilkeson || West Coast Gardening || Gardening Tips For my presentation on how to start seedlings indoors, see:

If the weather in March continues to warm up you could germinate some peas indoors for 2 weeks, then move them out to the garden and even try a few early potatoes. Sometimes March is a reasonable month for a head start on peas and potatoes, planting strawberries–and some years it isn’t.

Mason Bee notes: If you haven’t done so, it is time to put the cleaned cocoons of your mason bees (AKA Blue Orchard Bees) outdoor as the bees will be emerging soon (one or two have already started emerging from mine). The first bees to emerge are males, but females will be out pretty soon afterward so put out new nest tubes or cleaned nest boxes at the same time.

Salt Spring Garden Mentors wanted: For the last two years, a growing group of experienced gardeners, has been mentoring new or less experienced gardeners as they get started growing food. The organizer, Marian Hargrove, is looking for more mentors, as well as any new gardeners interested in being paired up with someone they can call for advice during the season. Contact her at:

Republished with permission from Linda Gilkeson’s Gardening Tips. See Linda’s website to sign up for her newsletter, purchase books, access free presentations and identify pests and diseases which may affect West Coast gardens.